thats about what i started at around 3 - 4 months ago. just make sure you keep good form and dont swing the weight up
i tend to go for 60 kg when doin barbell curls for 8-12 and 3 sets with a drop set on my last set, i have 25k each arm on dumbell curls same as above, and i tend to throw in a 40 kg of 21s on the barbell for 3 sets, kills your arms but makes me feel strong.
yes i do box but does that mean that i cannot incorporate weight training into my routine to gain the muscle before i tone back down, different fighters have different training routines and i guess mine just works for me
the biceps act as the triceps stabilizer and antagonist when the arm is fully extended and circumducted like when you twist at the end of a punch. if the bicep was not conditioned then the tricep would be more susceptible to injury.
Joe Frazier thinks bicep curls are no good for boxers because they shorten the muscle. I have no idea if that's right, but I can't see how they would really help boxers, so I don't do them.
I don't do them often, maybe once every 2 weeks or so. My arms and shoulders are getting out of proportion with the rest of my body. But when I do them I'm usually using around 95-105 lbs for 6 to 8 reps.